Best time to fly Houston to Springfield

Every month pooled across the years on record, so "July" means July generally rather than one particular July. Full IAH to SGF record →

Best month

September

84.7% on time · 59 flights

Worst month

December

56.5% on time · 46 flights

Month Flights On time Cancelled When late, by
January 56 71.2% 7.14% 108 min
February 52 73.5% 3.85% 92 min
March 61 68.9% 0% 105 min
April 77 77.6% 0% 92 min
May 99 74.2% 2.02% 135 min
June 63 63.8% 6.35% 177 min
July 62 71% 0% 90 min
August 80 75% 0% 179 min
September 59 84.7% 0% 44 min
October 62 74.2% 0% 69 min
November 53 76.9% 0% 173 min
December 46 56.5% 0% 69 min

What a seasonal pattern can and cannot tell you

Months differ for reasons that repeat — summer thunderstorms in the American interior, winter fog and de-icing in northern Europe, school holidays filling every seat and leaving no slack in the schedule. Those are real and they come back each year.

What the pattern cannot do is forecast a particular flight. A quiet month has late days and a bad month has punctual ones. Treat this as a way to choose between two dates you are indifferent about, not as a promise.